<html>

<head>
    <meta http-equiv="Content-Type" content="text/html;charset=utf-8">
    <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
    <meta http-equiv="Expires" content="0">
    <meta http-equiv="Pragma" content="no-cache">
    <meta http-equiv="Cache-control" content="no-cache">
    <meta http-equiv="Cache" content="no-cache">
    <title>管理中心</title>
    <style>
        iframe.normal{
            border:0;
            height: 100%;
            width:100%;
        }
    </style>
    <script>
        window.onload=function () {
            const session = window.sessionStorage;
            const userid = session.getItem("userid");
            const userpw = session.getItem("userpw");
            const iframe = document.getElementById("content");
            if(userid==null||userpw==null){
               iframe.src = "404.html";
            }else{
                iframe.src = "welcome.html";
            }
        }
    </script>
</head>
<body>
    <div>
        <div style="height: 64px;width: 100%;">
            <iframe src="admin_top.html"   noresize="noresize" marginwidth="0" marginheight="0" id="topFrame" scrolling="no" class="normal"></iframe>
        </div>
        <div style="width: 100%;">
            <div style="width:200px;height:100%;float:left;">
                <iframe src="left.html"  noresize="noresize" marginwidth="0" marginheight="0"  id="leftFrame" scrolling="no" class="normal"></iframe>
            </div>
            <div style="width:calc(100% - 200px);height:100%;float:left;border:0">
                <iframe src="" id="content"   noresize="noresize" marginwidth="0" marginheight="0"  name="main" class="normal"></iframe>
            </div>
        </div>
    </div>
</body>
<!-- 过时的写法 -->


</html>